Furnace for burning bituminous coal.



W. MoGLAVE.

FURNACE r011 BURNING BITUMINOUS GOAL.

APPLICATION FILED MAR. 24, 1913.

1,071,166. PatentedA 6,1913.

W. MOCLAVE.

F RNAUE FOR BURNING BITUMINOUS GOAL. U

I APPLICATION FILED MAR. 24, 1913.

1,071 ,1 66. Patented Aug. 26, 1913.

3 SHEETBSHEET 2.

W. MQGLAVE.

FURNACE FOR BURNING BITUMINOUS COAL.

APPLICATION FILED MAR. 24, 1913.

Patented Aug.26, 1913.

3 SHEETS-SHEET 3.

M V/Alllll W/AEIIIN f l l 5 ill " sn'rs PA ENT OFFICE.

WILLIAM MCCLAVE, OP SCRANTON, PENNSYLVANIA, ASSIGNOR TO MGCLAVE-BROOKS COMPANY, OF SCRANTON, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

FURNACE FOR BURNING BITUMINOUS COAL.

Specification of Letters Patent.

Patented Aug. 26,1913.

Application filed March 24, 1913. Serial No. 756,453.

To all whom it may concern Be it known that 1, WILLIAM lltiGCLAVn, a citizen of the United States, and resident of Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Furnaces for Burning Bituminous Coal; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, and to the figures and letters of reference marked thereon.

This invention relates to improvements in furnaces designed particularly for the consumption of bituminous fuel more especially as applied to the heating of steam boilers, the objects of the invention being to provide a highly efiicient furnace wiich will approximate more nearly the utilization of the theoretical value of the fuel than furnaces heretofore constructed; to eliminate as far as practical the escape of carbonaceous particles in the form of smoke; and to provide a structure which may be operated for long periods of time with a minimum of manual labor for clearing away accumulations of dust.

Referring to the accompanying drawings,--Figure 1 is a section longitudinally through a furnace embodying the present improvements, portions being shown more or less diagrammatically and some of the parts in elevation. Fig. 2 is a detail section showing the supporting connections between the arches over the secondary combustion chamber. F 3 is a section in a plane at right angles to the plane of Fig. 2. Fig. 4 is a detail top plan view showing portions of the arches and their supporting connections. Fig. 5 is a view corresponding to Fig. 1 but showing a modified arrangement of the secondary combustion chamber. Fig. 6 is a section in a plane at right angles to the plane of Fig. 5 and substantially on the line 66 of said figure.

Like letters of reference in the several figures indicate the same parts.

The form of furnace adopted for illustrating the invention is one particularly designed for heating steam boilers, which boilers may be of the water tube type diagrammatically indicated at A in Fig. 1, or

of the more ordinary tubular shell type indicated diagrammatically at 13 in Fig. 5.

The main combustion chamber of the fur nace is located in front of the forward end of the boiler, while a secondary combustion chamber is located beneath the forward end of the boiler, provision being made whereby there shall be an effective commingling of heated air and the gases from the fuel in the main combustion chamber before the air and gases are permitted to come into contact with the boiler or into contact with any cooled surface, the idea being to consume all of the fuel elements under conditions which will prevent any of the elements from being cooled or their temperature kept below the point of combustion. The gases resulting from the combustion may be caused to pass between the water tubes or around the shell of the boiler as the case may be in one, two or more passes by the interposition of suitable batl'le plates in the well understood manner, and therefore, I will not herein again refer to any particular arrangement of boiler setting or to means for conducting the gases around or through the same.

At the front end of the boiler there is an intermediate wall C which separates the main from the secondary combustion chambers, and the wall has a relatively large opening 0 therethrough located intermediate the top and bottom of the combustion chambers for the passage of the gases, heated air and products from one chamber to the other. The forward or main combustion chamber is provided with an inclined grate I), the fuel supporting surfaces of which may be of any known or desired character and formed of either movable or fixed sections. It is preferably, however, formed or fixed sections with the fuel supporting faces at an angle which is slightly less than the angle of rest of the fuel to be burned, and stoking mechanism such as that indicated at E, is provided for pushing the fuel onto and down said grate from the forward upper end. A dumping section F is provided in the lower end, the details of which form no part of the present invention.

lVithin the top or cover G of the front or main combustion chamber there is provided an arch H preferably of fire brick having between them apertures 71, usually formed by rounding or cutting away the edges of the brick, for the passage of air which is supplied to said apertures from a chamber it over the arch and communicating at the front with an air supply trunk 7L extending across the front of the furnace, and, if there be a battery of furnaces, preferably extending along the front of the whole battery.

The fuel supporting grate at its front end approaches closely to the arch forming a combustion chamber having its greatest height at the rear end, and distributing the fuel so that its gaseous and carbonaceous products may be mixed to the best advantage with the incoming heated air entering through the arch.

The secondary combustion chamber has its floor depressed below the bottom of the opening 0 in the intermediate wall so as to form a hopper bottom or receiver for dust and ashes which may be carried from the main combustion chamber into the secondary combustion chamber and there deposited. The secondary combustion chamber is separated from the boiler by a series of arches K which may be of fire brick or other refractory material, between which the gaseous products may leave the chamber and travel upwardly to the boiler. These arches K extend transversely across the secondary combustion chamber and, inasmuch as in use they become highly heated, it is found difiicult to maintain them in their proper relative positions for which reason it is desirable to place supporting connections between them and bet-ween the front arch and intermediate wall C as well as between the rear arch and bridge wall L. Conveniently and as shown in detail in Figs. 2, 3 and 4, the supporting connections M are in the form of downwardly tapered firebrick sections adapted to fit seats m in the side faces of the fire brick arches K,

and it is obvious that the connecting supports M may be located either centrally of the arches or at either side of the center, as may be found most desirable.

The receptacle formed by the bottom 0' of the secondary combustion chamber in Fig. 1 is preferably hopper-shaped, and the accumulations therein may be withdrawn through a suitable bottom opening communicating with a discharge duct 0 leading into the ash pit below the grate. The opening through the duct 0 is normally closed by a sliding or movable block 0 access to which may be had through a side door N in the secondary combustion chamher and the discharge of the accumulations may be effected by a steam ejector nozzle 0 directed into the duct 0 in a direction to withdraw the accumulations and force them forwardly into the ash pit.

In the particular embodiment illustrated in Fig. 1, the dust chamber P in rear of the bridge wall may be similarly cleared of accumulations through the duct 7) into which a jet from a steam nozzle p may be directed for blowing the accumulations forwardly into the ash pit.

In addition to the air supplied through the arched top of the front or main combustion chamber, air may be supplied through the bridge wall L, as for example by form ing therein passages indicated by the dotted lines at Z or any of the usual bridge wall constructions may be employed in which suitable means are embodied for supplying heated air to the products of combustion at the rear of the combustion chamber.

In lieu of the construction shown in Fig. 1 wherein the secondary combustion chamber is adapted to be cleared of accumulations by a jet of steam, the construction shown in Figs. 5 and 6 may be employed, wherein it will be seen that the bottom of the secondary combustion chamber is subdivided into two hopper-like receivers R and R, separated by an intermediate longitudinal wall R Each of the hoppers R, R communicates at its bottom through a duct or opening 7 with the ash pit below the grate and access to the hoppers may be had by a suitable instrument or hoe introduced through these openings, but the openings are normally adapted to be closed by doors or closures r of known construction.

In the construction shown in Fig. 5 it will also be noted that the heating and com mingling arches forming the top of the secondary combustion chamber are in stepped arrangement with the higher arches in front and the lower arches in the rear, next to the bridge wall, but save for this arrangement the construction is preferably similar in all respects to that described in connection with Fig. 1.

With a furnace of the construction described, the gaseous and carbonaceous par ticles driven ofi from the fuel on the grate are supplied with air entering the main or forward combustion chamber through the arched top of the same and heated to a high degree. Said products and air in passing through the communicating opening between the combustion chambers are further commingled and heated by impingement against and radiation from the walls and the series of highly heated arches in the secondary combustion chamber. They are caused to eddy and whirl in said secondary combustion chamber, without being allowed to come into contact with any cooled surface, whereby combustion is effected under ideal conditions, leaving only the final gases and incombustible ashes which latter will drop to the bottom of the secondary combustion chamber and may be readily and conveniently removed as occasion demands.

It will be particularly noted that all of the surfaces with which the gaseous and carbonaceous materials and air supplied thereto are brought into contact during the combustion period are of fire brick or equivalent material not liable to be destroyed by the intense heat to which they are subjected and all of the parts become highly heated during the operation and radiate their heat back into the gases and air so as to elfect a uniform and thorough heating of the whole of the same, thereby preventing any portion from escaping before combustion is complete, but at the same time the gases resulting from the combustion are free to flow or pass from the secondary combustion chamber for utilization in heating the steam boiler whereby practically none of the heat of combustion is lost or dissipated without performing useful work.

Obviously the arrangement is well adapted for use either with draft forcing means which will force the heated air in through the arch of the main combustion chamber and into the ash pit, or with natural draft appliances wherewith the air is drawn by a stack or other means through the con'ibustion chambers and around the boiler.

Having thus described my invention, what I claim. and desire to secure by Letters Patent of the United States, is,

1. In a furnace such as described, the combination with a main combustion chamher having an inclined grate therein and a horizontal arch above said grate having air feeding passages therein, of a secondary combustion chamber in rear of and communicating with the main combustion chamber, said secondary combustion chamber being defined at its rear end by a bridge wall and having a series of horizontal arches at the top through between which the gases from the combustion chamber pass into contact with a boiler located above said arches.

2. In a furnace such as described, the combination with a main combustion chamber having an inclined fuel supporting grate therein, the top of said combustion chamber being substantially horizontal and provided with air passages communicating with an air supplying duct for furnishing heated air to the combustion chamber and an intermediate wall. in rear of said combustion chamber having an opening therethrough,

of a secondary combustion chamber located in rear of said wall and defined at its rear end by a bridge wall, the bottom of said secondary combustion chamber being depressed. below the bottom of the opening through the intermediate wall and the top of said secondary combustion chamber being formed by av series of horizontal fire brick arches extending transversely across the combustion chamber, said arches being 1nutually supported one by the other at a point intermediate the ends and having openings therebetween for the passage of gases from the combustion chamber.

3. In a furnace such as described, the combination with a main combustion chamber having an inclined grate and arched top provided with air supply passages therein, of a secondary combustion chamber defined by a wall located intermediate the chambers and a rear bridge wall, the top of said secondary combustion chamber being formed by a series of transverse arches through between which the gaseous products of cone bustion escape, and said secondary comlimstion chamber having a hopper bottom with a passageway extending from said hopper bottom through the intermediate wall below the fuel supporting grate.

4:. In a furnace such as described, the combination with the main con'ibustion chamber having an inclined grate therein and a tire brick arch forming the top of said combustion chamber and provided with passages for supplying heated air to the chamber, a secondary combi'istion chamber in rear of the main combustion chamber and having in its upper portion a series of transverse [ire brick arches with passages between the same for the passage of products of combustion, an intermediate wall between said combustion chambers having an opening therein for the passage of products of combustion, a bridge wall forming the rear end of the secondary combustion chamber and intermedi ate fire brick supports seated between the arches in the secondary combustion chamber and between said arches and the front and rear walls.

l/VILLIAM MGGLAVE. lVitnesses ALEXANDER S. STEWART, THOMAS DURANT.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

